Combination gas and oil burner



W. W. STEVENSON AND 0. H. BATHGATE.

. COMBINATION GAS AND OIL BURNER. APPLICATION FILED SEPT. 9, 1918.

1L,4L85,991L a Patented-Nov, 21, 1922 A TTORNEY.

WELBUR W. STEVENSON AND OWEN H. BATHGATE, F V J'ILT'ZZINSBUHG PENNSYLVANIA, ASSIGNUBS TO ANTHONY COIL PANY, 0'5 LONG ISLAND CITY,

A CORPORATION OF NEW YORK.

new YORK,

CONIBINATIQN GAS AND OIL BURNER.

Application filed September To all whom-it may concern I Be it knownthat we, WiLnUn W. STEVEN- so and Owen H. Ba'rnox'rn, citizens of theUnited States, residing at \l'ilkinsburg, in the county of Allegheny andState of Pennsylvania, have invented certain new and useful Improvementsin Combination Gas and Oil Burners, of which the following is aspecification.

This invention relates to improvements in fuel burners and moreespecially to burners of the externally mixing low pressure air type ofthe class which are equipped with means to enable the burner to useeither liquid fuel or gas should such exigency arise. and it is theparticular object to provide a burner of this class with suchattachments as to enable the burner to perform its functions atextremely low gas pressure and is an improvement over the devicedisclosed in our application Serial No. 226,871 filed April th, 1918.

Other objects of our invention will appear in the followingspecification in which a preferred form of our fuel burner is described.

The invention is illustrated by the aid of the accompanying drawing inwhich Fig. 1 is a vertical longitudinal sectional view of the burner;

Fig. 2 is a transverse cross-sectional view taken along the plane line.in 1; 4

Fig. 3 is an elevation of the gas nozzle proper and Fig. at a plan viewof this nozzle.

Like characters of reference denote similar parts throughout the severalviews and the following specification.

10 is a cylindrical casing of substantially l. shape; its shorter branch11 is threaded interiorly to receive an air supply pipe 12. T heterminal of the longer branch 13 of cas ing 10 is threaded exteriorly at14-. it tubular chamber 15, formed by a wall 16 extends through thecasing 10 in axial alignment with its longer branch 13. TVaii 16connects the chamber with the outer wall of casing 10 opposite itsshorter branch 11 and is threaded interiorly for connection with a gassupply pipe 17.

U; sing 10 is bored out adjacent to branch 11, to receive what will becalled hereafter an oil-spindle 18. This oil-spindle is of hollow cons'truction being provided with a 9, 1918. Serial No. 253,306.

central duct 19, and extends through the tubular chamber 15 in centralalignment therewith. 20 is an enlarged upper end of spindle. l8 threadedinternally to receive a sprayplug 2i of the usual design employed withthe low pressure air. externally atomizing, oil burner. 22 is a nozzlescrewed onto the exterior of the wall 16 of chamber 15. The interior ofthis nozzle 22. hereafter referred to as gas nozzle," is shapedconvergingly toward the outlet end of the burner. and terminates in atubular opening 23 in axial alignment with the spray plug 21. The outersurface of the gas nozzle 2; is provided with spirally arranged vanes Qlwhich follow in outline the contour of the interior of the gas nozzle.25 is a -ap adapted to screw onto the threaded end ll of branch 13 ofcasing 10 which cap is so shaped interiorl v as to form an annularpassageway 26 between the outer surface of the gas nozzle and theinterior of the cap. which passage 'ay is gradually decreasing indiameters toward the outlet end of the burner. its terminal 27 beingstraight and parallel with the interior opening 23 of the gas nozzle 22.lhe exterior of cap as is provided with lugs 25 to facilitate screwingthe same onto the threaded part ll.

29 is a reduced portion of oil burner spindle l8, projecting outside ofthe casing 10 and is threaded exter-iorly to receive a needle valve 30of standard construction; a spindle 31 of which controls a. port'32through which oil is admitted into duct 19 of spindle l3, suppliedthrough a pipe 33.

The operation of the device is as follows:

Uil is admitted, as is usual with oil burners J: 1. ,L i i or LlllSclass, through supply pipe 53 and needle valve 30, whence it passesthrough spray plug 21 out at the front end of the 'lourner, where itmixes with air low pressure, forced into the casing 10 through pipe 12,which pipe is of relatively large diameter necessary to supplysutiicient oxygen for perfeet combustion. This air is deflected by meansof cap 25 and more particularly through passage :26 toward the spray ofoil issuing from spray plug 21 and annular outlet 23 of nozzle Should itbe desired to change the fuel' 17 into the chamber 15 whence it issuesthrough the interior of the gas nozzle 22 out at the front end of theburner.

Air passing through the cap 25 by means of the spiral vanes 24 is givena circular motion, around the gas opening adjacent the burner outlet 23,resulting in a quicker and better mixture of gas. Furthermore, the air,under pressure, issuing from the annular outlet of cap 25 in a rotarywhirl, causes a partial vacuum to be created within the center of itscurrent with a subsequential sucking effect on the gas, drawing it fromthe burner in place of producing a back pressure, as is the commondifiiculty experienced with gas burners:

Actual tests have shown that burners of our construction may be operatedwith gas at the pressure of only the fraction of an ounce aboveatmospheric pressure, making this device particularly adaptable indistricts where natural gas at a very low pressure is prevalent.

It is understood that while we have above described our invention asapplied to one kind of burner of the low pressure. type, its use andapplication may be varied, and serve other kinds of burners as well.

Various changes in the form, proportion and minor details ofconstruction may be resorted to without departing from the principle orsacrificing any of the invention as defined in the appended claims.

\Ve claim:

1. In a fuel burner, a liquid fuelduct within the burner, a spray plugat the outlet end of the said fuel duct, a gas chamber surrounding thesaid duct, means to discharge either liquid fuel or gas at the outletend of the burner, an'air supply connection to the burner. an adjustableannular air passage at the outlet end of the burner, the said passagebeing so shaped and located as to create a. partial vacuum directlybeyond the gas chamber while air is being forced through the said airpassage, the outlets of the said air passage and the said gas cha1nberbeing located atsome distance beyond.

the said spray plug.

2. In a low pressure burner of the class described in which either gasor liquid fuel may be discharged at the outlet end of the burner, a fuelduct within the burner, a spray plug at the outlet end of the said fuelduct, means to deflect air against, respectively, the spray of liquidfuel or jet of gas,

the said means comprising an adjustable annular discharge nozzleprovided with a number of spirally arranged vanes, the said nozzle beingof substantially converging shape and located so that said air isdeflected into said spray of liquid fuel or said jet of gas externallyof the burner outlet, the outlet end of the said discharge nozzle beinglocated at some distance beyond the said spray plug.

ln a combination gas and oil burner of the character described, 'an oilduct within the burner, a spray plug at the outlet end of the said oilduct, an interiorly smooth gas nozzle converging toward the outlet endof the burner and an adjustable annular air nozzle surrounding the saidgas nozzle forming an air passage, the area of which is graduallydecreasing toward the outlet end of the burner, the respective outletsof the gas and air nozzles lying adjacent to each other and at somedistance beyond the said spray plug.

4. In a combination gas and oil burner of the nature described, an oilduct within the burner, a spray plug at the outlet endof the said oilduct, and interiorly smooth gas nozzle converging toward the outlet endof the burner and an adjustable tubular shell surrounding the said gasnozzle forming an annular air passage, the area of which is graduallydecreasing toward the outlet end of the burner, spirally' arrangedvanes.

within the said annular air passage whereby the air is given a rotarydirection while passing therethrough, the respective outlets of the gasand air nozzles lying adjacent to each other and at some distance beyondthe said spray plug.

5. In a combination gas and oil burner, a liquid fuel duct within theburner, a spray plug at the outlet end of the said duct, a gas nozzleconverging toward the outlet end, an adjustable tubular shellsurrounding said gas nozzle forming an annular air passage BATHGATE

